A. 90
B. 70
C. 40
D. 80
Answer: D
Solution:
To estimate the square of 9 to the nearest tens, we first calculate 9 squared:
9² = 9 x 9 = 81
Now, let’s round 81 to the nearest tens. The ones place digit is 1, which is less than 5. Therefore, the tens place remains 8, and the ones place becomes 0. The estimated square of 9 to the nearest tens is 80.